add comments; clarify debug log; tag test case

- multiple devices test case is tagged so that it
  will not run with the default test list using
  the [.] syntax

src/xlink/XLinkConnection.cpp

@@ -304,7 +304,7 @@ void XLinkConnection::close() {
     if(closed.exchange(true)) return;
 
     constexpr auto RESET_TIMEOUT = 2s;
-    constexpr auto BOOTUP_SEARCH = 5s;
+    constexpr auto BOOTUP_SEARCH = 5s;  // majority of usb reboots on Windows need more than 5 seconds; this leads to a cascade failure
 
     if(deviceLinkId != -1 && rebootOnDestruction) {
         auto previousLinkId = deviceLinkId;
@@ -428,7 +428,8 @@ void XLinkConnection::initDevice(const DeviceInfo& deviceToInit, XLinkDeviceStat
 
         const bool bootStatus = bootWithPath ? bootAvailableDevice(foundDeviceDesc, pathToMvcmd) : bootAvailableDevice(foundDeviceDesc, mvcmd);
         if(!bootStatus) {
-            throw std::runtime_error("Failed to boot device!");
+            // this throw will cause an app to crash if not caught by a try/catch around the app's `Device` constructor
+            throw std::runtime_error("Failed to begin the boot of a device!");
         }
     }
 
@@ -444,7 +445,7 @@ void XLinkConnection::initDevice(const DeviceInfo& deviceToInit, XLinkDeviceStat
         // Use "name" as hint only, but might still change
         bootedDescInfo.nameHintOnly = true;
 
-        logger::debug("Searching for booted device: {}, name used as hint only", bootedDeviceInfo.toString());
+        logger::debug("Searching for booted device: {}, name/path used as hint only", bootedDeviceInfo.toString());
 
         // Find booted device
         deviceDesc_t foundDeviceDesc = {};

tests/src/multiple_devices_test.cpp

@@ -103,7 +103,7 @@ TEST_CASE("Multiple devices with 50 messages each") {
     REQUIRE(finished);
 }
 
-TEST_CASE("Multiple devices created and destroyed in parallel") {
+TEST_CASE("Multiple devices created and destroyed in parallel", "[.][multi_test_devices]") {
     constexpr auto TEST_TIMEOUT = 30s;
     constexpr auto COLOR_FPS = 30;
     constexpr auto MONO_FPS = 30;